Tozadenant is an adenosine A2A receptor antagonist that has demonstrated efficacy in treating Parkinson's disease and other conditions affecting the central nervous system. Tozadenant can be used as an adjunct to levodopa in patients with Parkinson's disease who are experiencing end-of-dose wearing-off (motor fluctuations). This promising activity is limited by side effects associated with administration of tozadenant, which include dyskinesias, dizziness, nausea, flushing, and transient hypertension. Accordingly, new formulations are needed to realize the full benefit of tozadenant in levodopa-based treatment of Parkinson's disease and other therapeutic applications. The present invention provides new tozadenant formulations that meet this need.